A wavelength-switched optical network (“WSON”) consists of two planes: a data plane and a control plane. The data plane comprises wavelength division multiplexing (WDM) fiber links connecting optical cross-connect (“OXCs”) through a combination of several tens of wavelength channels. Optical end-to-end connections (i.e., lightpaths) are established in the optical domain and switched by OXCs with wavelength granularity. In WSONs the optical signal is switched with wavelength granularity, and therefore, the wavelength assignment process (selecting the carrier of each established lightpath) plays a crucial role in dynamic network operation. The dynamic provisioning and maintenance of lightpaths is managed by the control plane. The control plane is implemented on a separate network and typically employs one network controller for each node in the data plane. In this context, an optical network packet may include a generic frame of information transmitted over an optical network without reference to packet switching technology.
A server trail is a non-data communication channel link across a third-party network that connects two network domains. Specifically, a server trail provides a connection between optical networking system nodes through a third-party network.